For FTD, single-gene DNA-methylation promoter analysis was performed previously for MAPT, GRN, and C9orf72. For MAPT, no significant differences in DNA-methylation levels were previously seen36, whereas both GRN and C9orf72 were shown to contain DNA hypermethylation in the promoter region11,37. Here, C9orf72 is linked to frontotemporal dementia.